Heat dissipation device with heat pipe

ABSTRACT

A heat dissipation device includes a heat pipe. The heat pipe includes an evaporating section connecting with a heat spreader, a condensing section connecting with a fin assembly, and a connecting section interconnecting the evaporating section and the condensing section. The evaporating section of the heat pipe has a diameter smaller than that of the condensing section.

BACKGROUND

1. Technical Field

The disclosure relates to a heat dissipation device and, more particularly, to a heat dissipation device incorporating heat pipes for removing heat from an electronic device.

2. Description of Related Art

As computer technology continues to advance, electronic components such as central processing units (CPUs) of computers are being made to provide faster operational speeds and greater functional capabilities. When a CPU operates at a high speed in a computer enclosure, its temperature greatly increases. It is desirable to dissipate the heat quickly, for example by using a heat dissipation device attached to the CPU in the enclosure. This allows the CPU and other electronic components in the enclosure to function within their normal operating temperature ranges, thereby assuring the quality of data management, storage and transfer.

A typical heat dissipation device comprises a base contacting an electronic component, a fin assembly disposed on the base and a heat pipe connecting the base and the fin assembly. The fin assembly comprises a plurality of fins connected together. The base absorbs heat from the electronic component and directly transfers the heat to the fins through the heat pipe. By the provision of the heat pipe, heat dissipation efficiency of the heat dissipation device is improved.

However, since most parts of the heat pipe of the conventional heat dissipation device are even in diameters, which results in more material is used for forming the evaporating portion of the heat pipe when the evaporating portion can have a smaller diameter. Furthermore, the evaporating portion of the heat pipe, which has the same diameter as that of the condensing portion, sometimes may hinder the applicability of the heat pipe to dissipate heat from an electronic component which is miniature.

What is needed, therefore, is a heat dissipation device which can overcome the limitations described.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an isometric, assembled view of a heat dissipation device in accordance with one embodiment of the disclosure.

FIG. 2 is an isometric, exploded view of the heat dissipation device of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 shows a heat dissipation device in accordance with an embodiment of the disclosure. The heat dissipation device dissipates heat generated by an electronic device (not shown). The heat dissipation device comprises a heat spreader 10, a fin assembly 20 above the heat spreader 10, three heat pipes 30 thermally connecting the heat spreader 10 with the fin assembly 20, a fan 40 and two fixing brackets 50 fixing the fan 40 to the fin assembly 20.

Also referring to FIG. 2, the heat spreader 10 is made of metal such as aluminum, copper or an alloy thereof. The heat spreader 10 includes a bottom plate 12 and a top plate 14 above the bottom plate 12. The bottom plate 12 defines three parallel, spaced first grooves 122 in a top thereof. The top plate 14 includes a rectangular body 142 and four ears 144 extending outwardly from four corners of the body 142. The body 142 defines three parallel, spaced second grooves 146 in a bottom thereof, corresponding to the first grooves 122. The four ears 144 each define a through hole 148 adjacent to a distal end thereof. Four fasteners 149 extend through the through holes 148 and are fastened on the ears 144.

The fin assembly 20 comprises a plurality of spaced and parallel fins. The fins each are made of metal such as aluminum, copper or an alloy thereof. Two slits 22 are defined in the two opposite lateral sides of the fin assembly 20 and located adjacent a front face thereof. Three through holes 24 are defined vertically through the fin assembly 20 receiving the heat pipes 30.

The heat pipes 30 each have an L-shaped configuration and comprise an evaporating section 32, a condensing section 34, an arced connecting section 36 interconnecting the evaporating section 32 and the condensing section 34. The evaporating sections 32 of the heat pipes 30 are accommodated in channels cooperatively formed by the first and second grooves 122, 146 of the heat spreader 10. The condensing sections 34 of the heat pipes 30 are received in the through holes 24 of the fin assembly 20 and thermally connect the fin assembly 20. The evaporating section 32 of each heat pipe 30 is uniform and has a diameter smaller than that of the condensing section 34 which also has a uniform configuration. The diameter of the connecting section 36 of each heat pipe 30 gradually decreases from a first end connecting with the condensing section 34 to a second end connecting with the evaporating section 32. In other words, the connecting section 36 tapers from the first end connecting with the condensing section 34 to the second end connecting with the evaporating section 32. In this embodiment, the diameter of the condensing section 34 of each heat pipe 30 is 8 mm, and the diameter of the evaporating section 32 of each heat pipe 30 is 6 mm. The evaporating section 32 of each heat pipe 30 is perpendicular to the condensing section 34. The evaporating section 32 and the condensing section 34 of the heat pipe 30 located in a middle of the fin assembly 20 are coplanar, and the evaporating section 32 and the condensing section 34 of each heat pipe 30 located near the lateral side of the fin assembly 20 are non-coplanar.

The fan 40 includes a rectangular frame 42 and an impeller 44 received in the frame 42. The frame 42 defines four orifices 420 in four corners thereof.

The two fixing brackets 50 each include a mounting portion 52 and a positioning portion 54 bent from a side of the mounting portion 52. The mounting portion 52 defines an arced cutout 522 in another side thereof remote from the positioning portion 54. The mounting portion 52 defines two threaded holes 520 in two opposite ends thereof, corresponding to the orifices 420 of the fan 40.

In assembly, the top plate 14 of the heat spreader 10 engages the bottom plate 12 so that the first grooves 122 of the bottom plate 12 and the second grooves 146 of the top plate 14 cooperatively form the channels receiving the evaporating sections 32 of the heat pipes 30. The condensing sections 34 of the heat pipes 30 are received in the through holes 24 of the fin assembly 20. The positioning portion 54 of each fixing bracket 50 engages in a corresponding slit 22 of the fin assembly 20. Screws (not shown) extend through the orifices 420 in the fan 40 and engage in the threaded holes 520 of the mounting portions 52, thereby securely mounting the fan 40 on the fixing brackets 50.

In use, the evaporating sections 32 of the heat pipes 30 can rapidly transmit the heat absorbed by the heat spreader 10 to the condensing sections 34 of the heat pipes 30. Since the evaporating sections 32 are smaller than the condensing sections 34, material for manufacturing the heat pipes 30 is reduced; thus, the material cost is reduced accordingly. Meanwhile, the smaller evaporating sections 32 match a smaller heat spreader 10, which also saves material and improves feasibility and applicability of the heat spreader 10 in a limited space such as a computer enclosure.

It is believed that the disclosure and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention. 

1. A heat dissipation device, comprising: a fin assembly; a heat spreader; and a heat pipe comprising an evaporating section, a condensing section, a connecting section interconnecting the evaporating section and the condensing section, wherein the evaporating section of the heat pipe has a diameter smaller than that of the condensing section, the evaporating section connecting with the heat spreader, the condensing section connecting with the fin assembly.
 2. The heat dissipation device as claimed in claim 1, wherein the evaporating section of the heat pipe is perpendicular to the condensing section.
 3. The heat dissipation device as claimed in claim 1, wherein the evaporating section has a uniform configuration.
 4. The heat dissipation device as claimed in claim 1, wherein the condensing section has a uniform configuration.
 5. The heat dissipation device as claimed in claim 1, wherein the evaporating section and the condensing section is coplanar.
 6. The heat dissipation device as claimed in claim 1, wherein the evaporating section and the condensing section is non-coplanar.
 7. The heat dissipation device as claimed in claim 1, wherein the connecting section of the heat pipe tapers from an end connecting the condensing section to another end connecting the evaporating section.
 8. The heat dissipation device as claimed in claim 1, wherein the diameter of the condensing section of the heat pipe is 8 mm, and that of the evaporating section of the heat pipe is 6 mm.
 9. The heat dissipation device as claimed in claim 1, further comprising a fan mounted in front of the fin assembly and over the heat spreader for generating an airflow through the fin assembly.
 10. A heat dissipation device, comprising: a heat spreader having a plurality of ears each being mounted with a fastener; a fin assembly; and at least one heat pipe comprising an evaporating section contacting the heat spreader, and a condensing section contacting the fin assembly, wherein the evaporating section is smaller than the condensing section.
 11. The heat dissipation device as claimed in claim 10, wherein the at least one heat pipe further comprises a connecting section interconnecting the evaporating section and the condensing section, the connecting section of the at least one heat pipe tapering from an end connecting the condensing section to another end connecting the evaporating section.
 12. The heat dissipation device as claimed in claim 10, wherein the heat spreader comprises a bottom plate and a top plate above the bottom plate, the bottom plate defining a first groove in a top thereof, the top plate defining a second groove in a bottom thereof, the first and second grooves cooperatively forming a channel receiving the evaporating section of the at least one heat pipe.
 13. The heat dissipation device as claimed in claim 12, wherein the top plate comprises a rectangular body, the plurality of ears extending from corners of the rectangular body.
 14. The heat dissipation device as claimed in claim 10, further comprising a fan mounted on one side of the fin assembly.
 15. The heat dissipation device as claimed in claim 14, further comprising a fixing bracket, the fixing bracket comprising a mounting portion and a positioning portion bent from a side of the mounting portion, the fan being mounted on the mounting portion, the positioning portion engaging in a slit defined in another side of the fin assembly. 